my·cor·rhi·za or my·co·rhi·za 
(mī′kə-rīzə)
(mī′kə-rīzə)n. pl. my·cor·rhi·zae (-zē) or my·cor·rhi·zas or my·co·rhi·zae or my·co·rhi·zas
The symbiotic association of the mycelium of a fungus with the roots of a plant, as is found in the majority of vascular plants.
[MYCO- + Greek rhiza, root; see wrād- in the Appendix of Indo-European roots.]
my′cor·rhizal adj.